The present invention relates to a cyclic ring compound and a method for preparing the same and more particularly, to a condensed bicyclic disilanylene-acetylene compound and a method for preparing the same.
Various types of organic, metal organic, and inorganic materials are known to have unusually high anisotropic properties and potentially useful electric, optical, and/or magnetic properties. Such materials are known to be useful in fabricating electrically conducting materials, semi-conductors, electronic devices, and electromagnetic or acoustic sensors. The utility of some of these materials may frequently be limited by such factors as weight, mechanical fragility, fabrication problems, corrosion, scarcity, and high costs.
Electroconductive organic materials have properties which can overcome or minimize such problems, and have the capability to be easily fabricated into films, filaments, and other shapes. Some of these materials are simply an organic material containing a conductive material therein, such as a metal or graphite. Others comprise organic materials whose electrical conductivities are established by chemical doping with electron acceptor and/or electron donor dopants. In general, the materials susceptible of establishing such electrical conductivity are characterized by highly delocalized .pi. electron conjugation, as may be found in most cyclic compounds, or sometimes by .sigma.-electron delocalization which may be found in polysilanes as well as the Si-C heterocyclic compounds.
Electron delocalization between Si-Si .sigma. bonds and .pi. systems has been established for conjugated polysilyl compounds containing unsaturated or aromatic groups. Such .sigma.-.pi. electron delocalization results in a strong ultraviolet absorption around 220 to 270 nm. Especially strong ultraviolet absorption at 250 nm has been found in the strained cyclic disilanylene-acetylene compound shown in formula (I): ##STR2##
The compound of formula (IV) was obtained from the application of either heat or light to the nine-membered ring compound shown below. ##STR3##
The compound of formula (I), because of its strong absorption in the near 250 nm wavelength, should have a high degree of .sigma.-.pi. electron delocalization and therefore a high potential for use as an electroconductive material as well as an optical material. In addition, possibilities exist that the ring of the cyclic molecule might be opened and the cleaved molecule polymerized through the use of an anionic, cationic or radical reagent, including Na, K, methoxide, ethoxide, t-butoxide, lithium amide, sodium amide, acetylide, butyllithium, BF.sub.3, BCl.sub.3, AlCl.sub.3, TiCl.sub.4, triethylaluminium, azobisisobutyronitrile and benzoyl peroxide. Further, like polysilanes or polycarbosilanes, the compound of formula (I) should undergo conversion to silicon carbide when heated to high temperatures.
It is an object of the present invention to provide a new class of cyclic silane compound with .sigma.-.pi. electron conjugation, specifically, a condensed bicyclic silane compound, and a method for preparing the same.
A further object of the present invention is to
provide a novel condensed bicyclic disilanylene-acetylene compound and a method for preparing the same.
These and other objects of the present invention will become apparent from the description hereinafter.